Around and around the weight-loss merry-go-round we go. Another year, another resolution to shed the kilos.

A survey by the Dietitians Association of Australia reveals 42 per cent of young women are resolved to lose weight this year.

Nothing new here. They had the same resolution last year. Around the developed world, the situation is the same. One study found 95 per cent of 16- to 21-year-olds in Britain want to change their body shapes while about 63 per cent of American women want to lose weight.

In Norway, a study of 3500 young women showed 49 per cent wanted to change the way they looked and would consider cosmetic procedures, such as liposuction, to do it.

While many of them may succeed, 95 per cent of those who lose weight will regain the weight within a few years, and many will gain more weight than they originally lost.

These are sobering statistics and it raises the question: why do we keep doing it to ourselves? Why do we keep rehashing the same goal, a goal that rarely works and simply serves to make women – and men – feel bad about their bodies and berate themselves when they do not succeed?

"It's tricky," says the psychologist Deborah Thomas, who will run a "psychological perspective" course on weight loss at Sydney University next month. "On the one hand, it's important for us all to be healthy and if you're too overweight then it's healthy to lose weight. But putting an emphasis on perfection and not loving ourselves as we are [is not healthy]."

Tara Diversi, a dietitian and author of The Good Enough Diet, agrees. "By constantly telling yourself you're fat, you're not going to get thinner, you're just going to make yourself unhappy and [then probably] dull the anxiety with food."

Such thinking offers an insight into why it is such a sorry cycle and why so many people tell Diversi and Thomas they would be happy if only they could lose weight.

Many people delay getting on with a life plan until they have reached their desired weight but experts say the constant self-criticism is taxing.

Many dieters convince themselves their emotional "weight" would be lifted along with their kilos.

However, it rarely is. "If you lose weight is your life going to be better?" Diversi asks. "Will you be more attractive? Not necessarily. Will you be smarter? Definitely not. Will you be better at your job? No."

Ironically, placing yourself under pressure to lose weight and lose it fast can have the opposite effect. There are two reasons for this.

First, Thomas says, women and increasingly men are shamed by the weight-loss industry into thinking losing weight is easy. "Shame is a hidden emotion and a classic way of dealing with shame is to eat. It's a losing battle," she says.

Second, she points to a passage from Brian Wansink's book, Mindless Eating, which says it is not always easy or fast.

Being extreme in your approach "becomes stressful and stress is one of the things that make weight loss hard", Thomas adds.

'The stress response . . . includes insulin and leptin [the 'satiating' hormone] resistance, along with the increased production of neuropeptide Y.

"These changes collectively stimulate the appetite and make it incredibly difficult to maintain the low calorie intake. Moreover, we are likely to turn to comfort foods [those high in sugar and fat] in order to relieve this stress response."

The key is taking a gradual approach and looking at our lives in general.

"Happiness doesn't lie in external factors," Diversi says. "Particularly not in your body. People need to have a look at what they think will make their life better. It might be having the courage to do something for yourself . . . taking time for yourself, painting, swimming or playing soccer. I think weight loss should be a byproduct, not the goal."

Contradictory though it may seem, in focusing the goal away from weight, the results are often found. When we feel good, we care more about our health, we treat our bodies with more kindness and we produce different hormones more likely to lead to weight loss.

"Eating is nice, it's very, very pleasurable," Thomas says. But "often we're seeking to fill something other than hunger.

"I often say [to new clients] 'forget about weight loss, exercise and nutrition. Let's look at what's making you unhappy.' It can take quite a bit of time to get past the idea that weight is the problem.

"[But] it's important to be really honest with yourself about what's going on and try to be a bit kind to yourself. I often find that when [my patients] make these changes and have sorted out their relationships, improved their self-esteem and started to live their lives more fully, then the weight just drops '